Honig G R, Shamsuddin M, Mason R G, Vida L N
Proc Natl Acad Sci U S A. 1978 Mar;75(3):1475-9. doi: 10.1073/pnas.75.3.1475.
An electrophoretically slow-moving hemoglobin variant was identified in three members of a family originating from Southern Mexico. The variant, Hb Lincoln Park, made up approximately 14% of the total hemoglobin and appeared to have normal stability and functional properties. None of the individuals in whom the abnormal hemoglobin was present was anemic, but each had a mildly elevated reticulocyte count. Structural data suggest that the non-alpha chain of Hb Lincoln Park represents a betadelta gene-fusion product, with normal beta chain structure of the amino-terminal portion of the chain and delta sequences subsequently, the crossover point occurring between animo acid residues 22 and 50. An additional abnormality is the deletion of valine-137, a component of the delta gene-derived segment of the betadelta chain. To account for the development of this abnormal globin chain, a series of intergenic crossovers is proposed; the first, a nonhomologous crossover between the beta and delta genes, presumably gave rise to the betadelta fusion gene; two additional crossovers, one of them unequal, may then have occurred between the same beta and delta genes to produce the amino acid deletion.
在一个来自墨西哥南部的家族的三名成员中，鉴定出一种电泳迁移缓慢的血红蛋白变体。该变体，即血红蛋白林肯公园，约占总血红蛋白的14%，并且似乎具有正常的稳定性和功能特性。存在异常血红蛋白的个体均无贫血，但每个人的网织红细胞计数均轻度升高。结构数据表明，血红蛋白林肯公园的非α链代表一种βδ基因融合产物，其链的氨基末端部分具有正常的β链结构，随后是δ序列，交叉点出现在氨基酸残基22和50之间。另一个异常是缬氨酸-137的缺失，缬氨酸-137是βδ链中δ基因衍生片段的一个组成部分。为了解释这种异常球蛋白链的产生，提出了一系列基因间交叉；第一个是β和δ基因之间的非同源交叉，大概产生了βδ融合基因；然后，相同的β和δ基因之间可能又发生了另外两次交叉，其中一次是不等交叉，从而导致了氨基酸缺失。
